It is well known that marine vessel internal combustion engine exhausts may be beneficially discharged underwater for above water sound suppression purposes. Also, it is well known that marine vessels employ "fender" means for their protection against hull damage or the like when docking, and/or when coming into contact with other vessels.
However, an object of the present invention is to provide an improved single means for both conducting the engine exhaust discharge of vessels of the "SES" (Surface Effect Ship) type away from and aft of the personnel occupied portion of the vessel; as well as for protecting the hull from damages thereto during docking or other "working" maneuvers of such vessels. Furthermore, the engine exhaust system of the present invention provides means which automatically, beneficially regulates the cross sectional area of the engine exhaust system in response to alternative "on cushion" and "off cushion" operations of the vessel and the extent of conduit inflation. Whether the ship is patrolling "on cushion" or is "off cushion" with engines running, the previously encountered engine exhaust noise is reduced without requiring use of conventional type mufflers or the like; thereby effecting cost and weight reductions and contributing substantially to the comfort of the passengers and operational efficiencies of the crew.